The invention relates to communication method and apparatus, server and client on network, and program codes realizing communication method.
A camera control system for controlling a camera (e.g., panning, tilting and zooming of the camera) from a remote place is widely known.
In this system, even though the camera control is performed via a network, a device for camera control and a client device do not depend on common specification but on unique specifications (e.g., protocol and control information).
However, in recent years, the Internet has been becoming popular with rapidity, and there is an increasing need from end users to see video images sensed by a camera at a remote place via the Internet.
One means to meet this requirement is to periodically store a video image sensed by a camera, in a file, into a storage device of a server connected to the camera, and transfer the file to a terminal (client) that has accessed the server. On the end-user side, a browser, for example, is activated so as to display the video image.
However, this merely displays the video image as sensed, but cannot meet requirements to see, e.g., the image in a view a little shifted to either side, the image in a wider view, or the image expanded within the view.
The present applicant has proposed a system in which a camera can be freely controlled via the Internet.
However, there is yet room for improvement in this system.